New Delhi: The Congress today dared Prime Minister Narendra Modi and BJP chief Amit Shah to prove the party's majority in the Karnataka assembly if they were so confident of their numbers.

The Congress said it will observe "Save Democracy Day" tomorrow with party workers and leaders holding protest marches at all district and state headquarters to protest the decision of Karnataka Governor Vajubhai Vala inviting B S Yeddyurappa to take oath as chief minister.

New Delhi: The Congress today dared Prime Minister Narendra Modi and BJP chief Amit Shah to prove the party's majority in the Karnataka assembly if they were so confident of their numbers.

The Congress said it will observe "Save Democracy Day" tomorrow with party workers and leaders holding protest marches at all district and state headquarters to protest the decision of Karnataka Governor Vajubhai Vala inviting B S Yeddyurappa to take oath as chief minister.

Stepping up the attack on the BJP, Congress communications in-charge Randeep Surjewala dubbed Yeddyurappa as a "one-day chief minister" saying he lacked majority.

He said tomorrow's protest is to express anger over the manner in which "democracy was subverted" and the "Constitution was trampled" by the Karnataka Governor.

Congress general secretary Ashok Gehlot said the anti-defection law is applicable in the country and in no way the BJP can prove that they have the majority.

He said the sanctity of the Raj Bhawan has been "lowered" at the behest of the BJP and expressed confidence that they will win in the Supreme Court as truth will finally prevail.

"This taking over of Yeddyurappa is a backdoor entry, as neither the prime minister nor Amit Shah have attended his swearing-in today," Gehlot told PTI, alleging that Yeddyurappa has been sworn in till tomorrow when the Supreme Court hears them out.

The Congress and JD-S last night challenged the swearing- in of Yeddyurappa as Karnataka chief minister in the Supreme Court which gave a midnight hearing to their petition but did not give any relief. The hearing will continue tomorrow and Congress has expressed hope that they will get justice.

"Amit Shah dares to give us sermons on democracy. We challenge Prime Minister Narendra Modi and BJP chief Amit Shah that if you have the courage of conviction, we dare you to prove your majority on the floor of the House tomorrow itself and the truth will come and democracy will win as you will be decisively decimated and defeated," Surjewala told reporters.

He said in view of the Governor's "illegal" decision, the Congress president has decided that all party workers will observe May 18 as 'save democracy day', by holding dharnas and protests in every nook and corner of the country and expose "misdeeds" of Narendra Modi and Amit Shah.

Surjewala said that if allowing the single largest party was the law, then the BJP governments in Goa, Manipur and Bihar should resign and Congress should be allowed to form their governments.

"Yeddyurappa will turn out one-day Chief Minister His fate as CM is dependent on the court hearing," he said.

"How come the Governor invite them to form government when the BJP does not have numbers to do so the Governor has encountered the Constitution twice he has murdered democracy, Surjewala said, alleging that the governor was working at the behest of the BJP's central leadership.

The Congress leader attacked Karnataka Governor Vajubhai Vala, accusing him of "encountering" Constitution twice, first by inviting the BJP to form government and then by allowing Yeddyurappa to take oath today, while the matter is being heard by the Supreme Court.

Attacking the Congress earlier in the day, Shah said that democracy was murdered the moment a "desperate" Congress made an "opportunist" offer to the JD(S) to form the government in Karnataka for "petty political gains".

The 'Murder of Democracy' happens the minute a desperate Congress made an 'opportunist' offer to the JD(S), not for Karnataka's welfare but for their petty political gains. Shameful!" he said in a tweet.

The BJP has emerged as the single largest party in the southern state winning 104 seats, but is short of a simple majority.

On the other hand, the Congress and JD(S), which have already announced post-poll tie-up, have won 78 and 37 seats respectively and claimed before Vala to have numbers to form government in the state.